Potential of the point in the origin

[cdummie]

Homework Statement

Find the potential of the point in the origin in regard to referring point at infinity if there's charged line laying on x-axis as shown in the picture.

Homework Equations

The Attempt at a Solution

I know two ways to find a potential:

V=∫dV and V=∫E*dl

using first formula i have dv=dQ/4πε₀r and i have Q=Q'dl but i don't know how to integrate that, i mean i have dl and i don't know what to do next.

 

[mfb]

Integrate along the line from -a to a?

I don't think the potential is well-defined, however.

 

[cdummie]

Integrate along the line from -a to a?

I don't think the potential is well-defined, however.

When i integrate from -a to a i get V=∫dQ/4πε₀r=Q'/4πε₀∫dl since ∫dl=2a i get V=Q'2a/4πε₀r but this seems way to easy, so I am not sure is it correct.
I don't know what you mean, i have to find the potential at point B(0,0) and referring point is at infinity. That is how it's defined.

 

[mfb]

Setting up the integral is easy.

I don't know what you mean, i have to find the potential at point B(0,0) and referring point is at infinity. That is how it's defined.

Yes, but you cannot do this if the integral diverges.

 

[rude man]

When i integrate from -a to a i get V=∫dQ/4πε₀r=Q'/4πε₀∫dl since ∫dl=2a i get V=Q'2a/4πε₀r but this seems way to easy, so I am not sure is it correct.

what is r?
I don't know what you mean, i have to find the potential at point B(0,0) and referring point is at infinity. That is how it's defined.[/QUOTE]
what mfb means is the potential at the origin is infinity. You have been given an impossible assignment!